If you're a student with solid knowledge of both Python and XML/HTML, and you're looking for a GSoC project that's both interesting and challenging, start by reading my own ideas for performance work. The Genshi code makes intensive use of Python language features such as closures and generators, and then there's also AST transformation and bytecode generation going on. The thing is that much of the low-hanging fruit for optimization has already been picked. In trunk we even have a _speedups extension written in C. So making major advancements in performance will require some thinking outside the box.